Walker said that he is "thrilled" to be joining the team.
The Football Focus host will be on the red sofa Monday to Wednesday alongside co-host Louise Minchin from Monday 29 February.
For an insight into the day job of the BBC Director-General two years into his role, I pop into Tony Hall's plate-glass eyrie at New Broadcasting House. I arrive in the aftermath of one of the regular encyclicals that DGs dispense.
He's sung the praises of the BBC's place in a "thriving, free and competitive market", an alternative to what a colleague terms the "Joni Mitchell" school of heartstring-tugging about the Beeb's innate brilliance.
